Stability analysis of the underground openings under earthquake induced dynamic loads has been carried Out for the four underground openings, which exist at Koyna H.E Project, Koyna, India. Vertical and horizontal displacements, maximum compressive and tensile stresses occurring in the vicinity of these openings have been computed and are compared vis-it-vis the values obtained from the static analysis. A reasonably good agreement between the results has been noted. The mininium major principal stresses (tensile), which exist only in the vicinity of the underground openings. when static analysis is conducted are noted to spread over the entire rock mass when dynamic analysis is performed. The study presents a methodology, which can be used for checking the stability of the underground openings, under seismic loading conditions.